Ribera said the government would present a draft plan to combat climate change, which had been due to be sent to the European Union for approval by the end of last year, to parliament on Feb. 22.

Under a draft bill prepared last year, the government aims to ban sales of petrol, diesel and hybrid cars from 2040 and encourage the installation of at least 3,000 megawatts a year of renewable capacity such as wind farms and solar plants.

Phasing out nuclear power, which accounts for a little over 20 percent of mainland Spain's electricity, was a campaign pledge for the governing Socialists, who took office last summer after toppling their conservative predecessors in a confidence vote.

Spain's nuclear plants, which started operating between 1983 and 1988, are owned by Iberdrola, Italian-owned Endesa, Naturgy and Portugal's EDP.